package response;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

@WebServlet("/Vc_demo1")
public class Verification_code_demo1 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doPost(req,resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        int width = 100;
        int height = 50;
        //1.创建对象，在内存中生存图片
        BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
        //2.美化图片
        //2.1 填充背景色
        Graphics g = image.getGraphics();
        g.setColor(Color.pink);
        g.fillRect(0,0,width,height);
        //2.2 画边框
        g.setColor(Color.blue);
        g.drawRect(0,0,width-1,height-1);

        //2.3 写验证码
        String str = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
        //生成随机角标
        Random ran = new Random();
        for (int i=1;i<5;i++) {
            int index = ran.nextInt(str.length());
            char ch = str.charAt(index);
            g.drawString(ch+"",width/5*i,height/2);
        }

        //2.4 画干扰线
        g.setColor(Color.green);
        for (int i=0;i<10;i++){
            int x1 = ran.nextInt(width);
            int y1 = ran.nextInt(height);
            int x2 = ran.nextInt(width);
            int y2 = ran.nextInt(height);
            g.drawLine(x1,y1,x2,y2);
        }
        //3.将图片输出
        ImageIO.write(image,"jpg",resp.getOutputStream());
    }
}
